Senior Software Engineer - PaCI foundation and Platform AI - USDS

Responsibilities

About the Team

The USDS JV Platform and Community Integrity (PaCI) team is the architectural backbone of Tik Tok's Risk & Integrity ecosystem in the U.S. We drive end-to-end integrity for Tik Tok and its expanding ecosystem, including Lemon8 and emerging affiliate platforms, by leveraging localized U.S. data and state-of-the-art AI/LLM capabilities.

Within this organization, the PaCI Foundation and Platform AI team builds and maintains Tik Tok's U.S. risk control ecosystem. Our mission is to deliver core risk management systems, anti-automation fraud tools, and threat intelligence pipelines. We architect the core machine learning infrastructure and risk AI platforms required to protect our billion-user ecosystem from complex, adversarial threats. Joining our team offers engineers the unique opportunity to develop, automate, and validate large-scale distributed systems while tackling the intricate engineering challenges of global scale.

• - Develop, implement, and maintain high-throughput, low-latency systems such as Decision Engines, Data Platforms, and Horizontal ML/AI architectures. Write clean, production-ready backend code (Go/C++/Python) to serve defense algorithms at a global scale.
• - Work on infrastructure and tools to enable the construction, deployment, and serving of risk defense algorithms and machine learning models rove capacities for risk prevention, perception, and remediation across various Tik Tok businesses. Work closely with cross-functional partners to understand business needs and design effective platform solutions.
• - Drive the day-to-day development, operations, and technical excellence of the platform, and continuously improve performance, reliability, and scalability.
• - Design and implement robust automated testing frameworks, regression suites, and stress-testing tools for complex distributed systems and LLM behaviors. Leverage next-gen AI Agent capabilities to build advanced test automations.
• - Keep risk control solutions state-of-the-art regarding data security, modularization, privacy, and compliance.

Minimum Qualifications

• - Bachelor's degree, majoring in Computer Science or related fields
• - 3+ years of experience designing, building, and maintaining large-scale distributed systems.
• - Proficiency in one or more general-purpose languages, such as Go, C/C++, Java, or Python.
• - Problem Solving:
  Ability to think critically and decompose complex, ambiguous problems into clear, concise technical solutions.
• - Exceptional communication skills with a history of working effectively in cross-functional, multi-regional environments.

Preferred Qualifications

• - MS or PhD in Computer Science, Computer Engineering, or a related technical field.
• - Hands-on experience with high-throughput low latency infrastructure handling massive traffic (e.g., feature stores, model serving, or AI infra etc).
• - Background in Risk, Anti-Fraud, AI Safety or Trust & Safety domains.

Tik Tok USDS Joint Venture LLC is dedicated to the safety and security of millions of Americans who create, discover, and connect with what they love on the apps we operate. The Joint Venture has been established in compliance with the Executive Order signed by President Trump on September 25, 2025. Our foundation is a comprehensive data privacy and cybersecurity program we operate under defined safeguards to protect national security and secure U.S. user data, apps and the algorithm.

We safeguard the U.S. content ecosystem, holding decision-making authority for trust and safety policies and moderation. USDS Joint Venture helps ensure Americans can continue to express their creativity, discover new hobbies and interests, and build thriving communities and businesses on a global scale.

On-site presence across teams allows the company to operate with greater speed, alignment, and agility — especially in areas like real-time decision-making, team development, and integrated execution. As such, the company is shifting from a hybrid work model to a fully in-person schedule up to 5 days a week.

Inspiring creativity is at the core of Tik Tok's mission. Our innovative product is…